Rotary switch with selectively limited positioning

ABSTRACT

Rotary indexing switch which can be selectively limited for switching through one, two, three, or four positions. A disk is positioned between the base member and the knob of the switch mechanism. One of four spaced apart indentations in the disk is selected to engage a pin affixed to either the knob or the base member. A slot in the disk engages another pin affixed to whichever of the knob or base member does not have the first pin.

United States Patent 1 [111 3,767,880

Austin Oct. 23, 1973 ROTARY SWITCH WITH SELECTIVELY 3,430,515 3/1969 Lawrence, Jr. 74/553 LIMITED POSITIONING Charles W. Austin, Williamsville, NY.

GTE Sylvania Incorporated, Stamford, Conn.

Filed: Aug. 14, 1972 App]. No.: 280,358

Inventor:

Assignee:

U.S. Cl. 200/169 R, 74/10.41, 74/228, 74/327, 74/553 Int. Cl. II0lh 3/20, H01h 9/20 Field of Search 200/169 R, 155 K, 200/172 R, 172 A; 74/553, 527, 228, 10.41

References Cited UNITED STATES PATENTS Lawrence, Jr. 74/10.4l

Primary ExaminerDavid Smith, Jr. Att0rneyNorman J. OMalley et al.

[57] ABSTRACT Rotary indexing switch which can be selectively limited for switching through one, two, three, or four positions. A disk is positioned between the base member 6 Claims, 5 Drawing Figures PATENTEBncrza 1915 3767380 SHEET 2 BF 2 Fig. 4.

ROTARY SWITCH WITH SELECTIVELY LIMITED POSITIONING BACKGROUND OF THE INVENTION This invention relates to rotary switches. More particularly, it is concerned with rotary switches having limited angles of rotation which may be selectively varied.

In certain apparatus, such as, for example, small hand-held communication radios, it may be desirable to provide a capacity of several communication channels but be able to limit the number of channels available for use at any one time in a selective manner. For example, a communication radio may have the capability of employing up to four communication channels, and it may be desirable to selectively limit operation of the radio to only one, two, or three of the channels. The choice of a specific channel within the range selected typically is made by switching a rotary switch to the proper position for the desired channel.

SUMMARY OF THE INVENTION A rotatable shaft mechanism having selectively limited angular positions for use with a rotary switch may be employed to switch channels in a communication radio is provided by the mechanism in accordance with the present invention. The mechanism is relatively inexpensive by virtue of employing standard switch elements in combination with other uncomplicated structural elements. In addition, selecting angular positions to which the shaft is to be limited is easily accomplished.

A rotatable shaft mechanism in accordance with the present invention includes a base member and a shaft which extends from the base member and is mounted for rotary movement with respect thereto. The shaft may be the shaft of a rotary switch. A knob member is fixed to the shaft. A plate is disposed between the base member and the knob member and lies generally normal to the shaft. The plate has a central opening through which the shaft extends, and also has an arcuate opening. One of the members, for example the knob member, has a pin affixed to it which provides a projection for extending into the arcuate opening. The other member is selectively fixed to the plate by a locking means in a manner which permits the fixed angular relationship between the member and the plate to be changed. Thus, the possible angular positions of the knob member with respect to the base member are limited by the excursion allowed by the pin in the arcuate opening, and may be changed by changing the particular fixed angular relationship between the plate and the member.

BRIEF DESCRIPTION OF THE DRAWINGS Additional objects, features, and advantages of rotatable shaft mechanisms in accordance with the present FIG. 2B is a plan view of the shaft mechanism of FIG. 1 showing the elements arranged for switching to any one of the four possible switch positions;

FIG. 3 is an exploded view in perspective of an alternative embodiment of the rotatable shaft mechanism in accordance with the invention; and

FIG. 4 is a plan view of the shaft mechanism of FIG. 3 showing the elements arranged to permit switching to any of three of the four possible switch positions.

DETAILED DESCRIPTION OF THE INVENTION One embodiment of a rotatable shaft mechanism in accordance with the invention is illustrated in the exploded perspective view of FIG. 1. The mechanism is shown mounted in a housing 10 which may, for example, be the casing of a hand-held communication radio. The housing has an opening through which a shaft 11 extends. The shaft is mounted for rotation in a base member 12 which is fixed to the housing 10.

The base member 12 may also include a detent or indexing arrangement which limits the shaft to movement in discrete angular increments through a fixed number of angular positions. Suitable miniature detent or indexing arrangements are disclosed in application Ser. No. 148,782, filed June 1, 1971, by Norman R. Diehl entitled Miniature Detent Mechanism and in application Ser. No. 148,781, filed June 1, 1971, by Raymond G. Hartman entitled Miniature Indexing Mechanism. Both applications are assigned to the assignee of the present invention. In the specific embodiment under discussion, the shaft indexes through discrete positions in increments of 30. A stop pin 13 extends outward from the shaft 11 so as to abut a shoulder 14 in the base member 12 and limit rotation of the shaft in the counterclockwise direction. As shown in FIG. 1, the shaft 11 is associated with a rotary switch 15. The shaft 11 has a flat surface and is adapted to fit in a suit able recess in a knob 20. The knob 20 may be fixed to the shaft 11 as with a set screw 21.

The elements as described herein up to this point are typical standard items as employed in rotary indexing switches. In accordance with the present invention, there is included between the knob 20 and the housing 10 a plate or disk 25 of generally circular configuration. The disk 25 has a central opening 26 to accommodate the shaft 1 1. The disk fits within a counter bore or circular depression 16 in the housing 10 of slightly larger diameter than the disk. Thus the disk is maintained centered with respect to the shaft and its upper surface is flush with the surface of the housing 10. The disk also has an arcuate opening 27 which extends in a circular arc centered about the center of the disk. The opening 27 as shown subtends a central angle of The disk also has a plurality of indentations 31, 32, 33, and 34 along a portion of its periphery which also subtends a central angle of 90. The indentations 31-34 are each adapted to be capable of receiving a pin 35 affixed to the housing 10. A pin 36 extending from the underside of the knob 20 is adapted to engage the arcuate slot 27.

The manner in which the mechanism serves to control the number of possible positions of the switch is more clearly illustrated in FIGS. 2A and 2B which show the disk 25 on the housing 10 and the knob 20, in phantom, in its assembled position. In the specific arrange ment illustrated in FIG. 2A, the parts are assembled with the disk 25 placed in the depression 16 on the housing with the first peripheral indentation 31 meshing with the pin 35. The disk 25 is thus locked in the position shown in FIG. 2A. The pin 36 on the knob extends into the arcuate slot 27 at its clockwise end.

Thus, by virtue of this particular arrangement, selected by engaging the first indentation 31 with the pin 35, the knob 20 cannot be moved in a clockwise direction beyond position 1 since the pin 36 in the knob abuts the disk at the clockwise end of the slot 27. counterclockwise movement of the knob 20 is not prevented by the slot 27 and pin 36 combination. However, if as shown in FIG. 1 a stop pin 13 is provided on the shaft 11 and abuts the shoulder 14, movement in the counterclockwise direction is also prevented, and the mechanism is locked with the knob 20 and shaft in position 1.

FIG. 28 illustrates another arrangement of the assembled parts of the mechanism of FIG. 1. In this particular arrangement, the disk 25 is placed on the housing 10 with the pin 35 engaging the fourth indentation 34. The disk 25 is thereby fixed in the position shown in FIG. 2B. When the knob 20 is mounted on the shaft 11, the pin 36 engages the arcuate slot 27. The arcuate slot 27 permits movement of the pin throughout its length and thus the knob 20 may be rotated through an arc of 90 to any one of the four positions 1, 2, 3, or 4. With a 30 detent arrangement, the shaft positively indexes at each of the four positions.

The mechanism may also be assembled with a disk 25 placed so that the pin engages either of the other two indentations 32 or 33. If the pin 35 engages the second indentation 32, the shaft may be switched through positions I and 2. If the pin 35 engages the third indentation 33, either positions 1, 2, or 3 may be chosen. Thus, by virtue of the assembled position of the disk 25 with a selected one of indentations 31-34 engaging the pin 35, the switch can be limited in one, two, three, or four positions. The arrangement can be changed simply by removing the knob 20, reorienting the disk 25 as desired, and replacing the knob 20.

An alternative embodiment of the shaft mechanism in accordance with the present invention is illustrated in the exploded perspective view of FIG. 3. A housing 40, a shaft 41, a base member 42, a stop pin 43, a shoulder 44, and a switch are similar to the corresponding elements illustrated in FIG. 1 and discussed previously. Similarly, a knob and set screw 51 are similar to corresponding elements in FIG. 1. A circular disk 55 is also similar to that shown in FIG. 1 having a central opening 56, an arcuate slot 57 subtending a central angle of 90, and a plurality of indentations 61, 62, 63, and 64 along the periphery of the disk and subtending a central angle of 90. The housing 40 has a pin 65 affixed thereto and the knob 50 has a pin 66 affixed thereto. The disk 55 fits within a depression 46 in the surface of the housing 40. The depression has an enlarged portion to accommodate the pin 66 on the knob 50.

One of the four possible arrangements for assembling the mechanism of FIG. 3 is illustrated in FIG. 4. In this embodiment of the invention the disk is fixed selectively with respect to the knob 50 rather than with respect to the housing 40 as in the embodiment of FIG. 1. As shown in FIG. 4, the pin 66 of the knob 50 engages the third indentation 63 in the disk 55 and thus 6 is fixed for rotation therewith. In FIG. 4, the knob 50 is shown in its most clockwise position, position 3, with pin 65 which is fixed to the housing 40 abutting the end of the slot 57. The shaft may, of course, be rotated to either position 1 or 2, further counterclockwise movement being prevented by the stop pin 43 and the shoulder 44. The shaft may not be rotated clockwise further to position 4 because the portion of the disk at the end of the slot 57 abuts the pin 65.

The parts of the mechanism may also be assembled with the pin 66 of the knob 50 inserted in either of the other indentations 61, 62, or 64 so as to fix the disk 55 with respect to the knob 50 in a different angular position. The shaft is thereby limited to position 1, positions 1 and 2, or positions 1, 2, 3, and 4, respectively.

While there have been shown and described what are considered preferred embodiments of the present invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention as defined by the appended claims.

What is claimed is: 1. A rotatable shaft mechanism having selectively limited angular positions including a base member; a shaft extending from said base member and mounted for rotary movement with respect thereto; a knob member fixed to said shaft; a plate disposed between the base member and the knob member and lying generally normal to said shaft, said plate having a central opening through which said shaft extends and having an arcuate opening therein; one of said members havinga pin affixed thereto and extending into said arcuate opening; and locking means for selectively fixing the plate to the other of said members in different angular ralationships about the shaft whereby the possible angular positions of the knob member with respect to the base member are selectively limited; said locking means including a second pin fixed to the other of said members;

and

a plurality of pin receiving openings in said plate, each of which is adapted to receive said second pin, rotary movement between the plate and the other of said members being prevented by the pin abutting the walls of the pin receiving opening when the pin is in an opening.

2. A rotatable shaft mechanism in accordance with claim 1 wherein said plate is a circular disk;

said pin receiving openings are a plurality of equally spaced indentations along the periphery of the disk, the plurality ofindentations subtending a central angle of a particular value; and

said arcuate opening lies along a circular are having its center at the center of the shaft and subtends a central angle of said particular value.

3. A rotatable shaft mechanism in accordance with claim 2 wherein said first-mentioned pin is affixed to said base member; and

said second pin is affixed to said knob member.

4. A rotatable shaft member in accordance with claim 2 wherein said first-mentioned pin is affixed to said knob member; and

v 6 claim 5 including detent means for causing the shaft to index in a predetermined number of positions whereby the number of possible positions of the shaft is selectively varied by selectively changing the fixed angular re lationship between the plate and the other of said members. 

1. A rotatable shaft mechanism having selectively limited angular positions including a base member; a shaft extending from said base member and mounted for rotary movement with respect thereto; a knob member fixed to said shaft; a plate disposed between the base member and the knob member and lying generally normal to said shaft, said plate having a central opening through which said shaft extends and having an arcuate opening therein; one of said members having a pin affixed thereto and extending into said arcuate opening; and locking means for selectively fixing the plate to the other of said members in different angular ralationships about the shaft whereby the possible angular positions of the knob member with respect to the base member are selectively limited; said locking means including a second pin fixed to the other of said members; and a plurality of pin receiving openings in said plate, each of which is adapted to receive said second pin, rotary movement between the plate and the other of said members being prevented by the pin abutting the walls of the pin receiving opening when the pin is in an opening.
 2. A rotatable shaft mechanism in accordance with claim 1 wherein said plate is a circular disk; said pin receiving openings are a plurality of equally spaced indentations along the periphery of the disk, the plurality of indentations subtending a central angle of a particular value; and said arcuate opening lies along a circular arc having its center at the center of the shaft and subtends a central angle of said particular value.
 3. A rotatable shaft mechanism in accordance with claim 2 wherein said first-mentioned pin is affixed to said base member; and said second pin is affixed to said knob member.
 4. A rotatable shaft member in accordance with claim 2 wherein said first-mentioned pin is affixed to said knob member; and said second pin is affixed to said base member.
 5. A rotatable shaft mechanism in accordance with claim 2 including a stop means for limiting rotation of said shaft in one direction whereby the amount of rotation of the shaft is selectively varied by selectively changing the fixed angular relationship between the plate and the other of said members.
 6. A rotatable shaft mechanism in accordance with claim 5 including detent means for causing the shaft to index in a predetermined number of positions whereby the number of possible positions of the shaft is selectively varied by selectively changing the fixed angular relationship between the plate and the other of said members. 